[TheForge] Welding Liberty Ships

[gblacksmith]

Ship Folks:  This last seems on the money.  I had first-hand experience 
withthe results of poor welding and fit-up up components in the "American 
Sun" class tankers built in the 1970s.  These vessels were built "on spec" 
and the construction program was a traininng vehicle for job-creation.  In 
one case, of these tankers experienced fracturing in the cargo pumproom 
bulkheads, which were shored with wooden shoring beams.  I recall that this 
shoring was in place during one voyage to Valdez, AK, and during cargo oil 
loading there.  I would have hated to be in that pumproom when the bulkhead 
failed...smothered by heated North Slope Crude.  The USCG inspectors, when 
they saw this state of  affairs, were unimpressed.

I wonder if the quality of steel designated as suitable for hull and 
bulwarks plating on ships can be vouched for, given the potential for 
inclusions  when undifferentiated scrap is part of the melt.  I would expect 
that the lots of steel used in the plating would be independently tested, 
but I'm not certain.




----- Original Message ----- 
From: <xlch58 at swbell.net>
To: <munlaw2 at hcsmail.com>; "Sponsored by ABANA" <theforge at mailman.qth.net>
Sent: Thursday, March 03, 2005 6:57 AM
Subject: Re: [TheForge] Welding Liberty Ships


>I have heard this repeated before, but the engineering texts that I have 
>read case studies in did not mention it.  If anything, poor technique was 
>cited more often for rivet failures.    The American Welding Society tell 
>it different too:
>
> <http://www.aws.org/about/blockbuster.html>
>
> Here is the relevant excerpt:
>
> "During this period of assimilation, eight Liberty ships were lost due to 
> a problem called brittle fracture. At first, many blamed welding, but 
> history would soon prove that the real cause of brittle fracture was 
> steels that were notch sensitive at operating temperatures. The steel was 
> found to have high sulfur and phosphorus contents. Another cause was 
> design-related discontinuities, such as hatch openings, vents and other 
> interruptions in the structure. By far the highest incidence of fracture 
> occurred under a combination of low air temperature and heavy seas."
>
>
> Charles
>
> Ron Childers wrote:
>
>>The welders were paid by the number of rods they burned. When the ships
>>broke apart the inspectors found that the rods were just thrown into the
>>keel and welded over. This practice consumed large quantities of rods, but
>>resulted in very poor welds.
>>
>>Ron C
>>
>>-----Original Message-----
>>From: theforge-bounces at mailman.qth.net
>>[mailto:theforge-bounces at mailman.qth.net] On Behalf Of David E. Smucker
>>Sent: Wednesday, March 02, 2005 8:19 PM
>>To: Sponsored by ABANA
>>Subject: Re: [TheForge] Welding advice -- Now Heavy Welds
>>
>>Chuck / James -- this all make sense -- the use of riveted structures for 
>>ships -- As almost all heavy industrial structural steel was still using 
>>riveted design well into the 1950's.  (I know that based on older mill 
>>building in the company I worked for being riveted construction.)  In fact 
>>if I remember this correctly some of the first welded ship construction 
>>was the "Liberty" Ships built during WWII and a number of these ended up 
>>with stress cracking failures while at sea.
>>
>>
>
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